The idea behind True20 is to provide a streamlined and simple ruleset that does not intrude into role-playing, but serves to facilitate it. Based on the core D20 mechanic, and published under the Open Gaming Licence, the fundemental idea is that a single roll of a D20 is all that you require to see if your character can do, well, whatever AND to discover the results of that action.

The Foreword gives a spot of history, the ruleset now presented was originally developed for the 'romantic fantasy' game Blue Rose on the grounds that many people who'd like to play that sort of game would be deterred by the heavy-duty rules-heavy nature of games like Dungeons & Dragons. While Green Ronin had intended to use the system elsewhere, they did not originally envisage a generic ruleset... until they heard what a wide range of games people were already using it for! And so a setting-independent ruleset came about.

Next, the Introduction begins with a fairly standard 'What is roleplaying?' piece, and then launches into the basics of how this particular ruleset works. Each character is defined by his Abilities (strength, intelligence and such like), his Role (3 core ones of adept, expert or warrior), his Skills and his Feats - all of which contribute positive or negative modifiers to apply to a single D20 roll against a Difficulty set by the Narrator (GM) based on what the character is trying to do. That's it. The rest of the chapter goes on to discuss the different situations in which you might want to roll, and what modifiers might apply depending on whether you are rushed or taking your time, will it be disasterous if you fail (you really, really want to succeed at defusing bombs, for example!) and the like.

Chapter 1 deals with Character Creation. A point allocation system, rather than die-rolling, is used so that you can build a character according to your vision of what he's like. Everything is explained clearly, so that you know what the consequences of your choices will be. A system of 'backgrounds' can be used to influence the effect of anything from a character's upbringing to his species, giving a collection of balanced advantages and disadvantages to the basic outline. An interesting feature is the concept of Role. Rather than having an array of character classes, like standard D20 games, the character is either an Adept, an Expert or a Warrior - his strength being in supernatural powers, skill use or combat respectively. This influences the skills and feats you choose later on. You can also round out a character by describing appearance, age, gender and selecting a virtue and a vice for him. Next the Conviction system is introduced - this reflects the determination that makes a character a 'hero' rather than your everyday sort of fellow, and is a pool of extra points that can be used to sway things in your direction at a critical point - like Spycraft Action Dice and similar mechanics.

Chapter 2 looks at Skills. They are used in the conventional manner of having 'ranks' in chosen skills which, along with the appropriate ability modifier, are combined with a D20 roll to see how well you did. As explained in the previous chapter, you get a certain number of ranks to begin with (depending on Role and intelligence of the character), and with each increase in level you get a few more to spend. Each skill listed comes with details of what it applies to and how it can be used. Some - like knowledge or perform - need you to specify to what they apply.

Next, Chapter 3 gives a similar treatment to Feats. These are defined as special abilities which a player character might have, but which are not usually available to ordinary people. They may provide a special gift or talent, and can be used to customise your character's capabilities. You start with a set number chosen from a general list or a subset dependent on your Role, and add more as you rise in level.

Chapter 4 then looks at Supernatural Powers. For a character with the Adept Role, these can be obtained in the same way as Feats. The definition is broad: these Powers might be magical spells or divinely-bestowed abilities, or powers of the mind. Or something completely different like a hacker in a virtual reality world. When using a Power, a bonus based on Adept rank +3 and the controlling ability modifier is added to the D20 roll. Some Powers are tiring to use, and the Adept has to guard against becoming too fatigued. It's all left quite vague - deliberately so, as the nature of Powers available will depend on the setting in which you play.

Next comes Chapter 5: Equipment. As well as actual gear, it also looks at wealth and spending in general. A character has a basic Wealth score, which is compared against the value of whatever he wants to buy - a neat abstraction for those who do not want to keep track of cash, but which can take away one of the main motivators for adventuring - getting loot so that you can buy more stuff! When it gets to weapons, you get the usual descriptions you would expect, except that damage is presented as a modifier rather than a die type or number of points. This hooks in to the combat system, which is one of the main differences between this ruleset and standard D20 systems.

And so on to Chapter 6: Playing the Game. It's all about providing the mechanics to enable characters to actually do things. Starting with Physical Actions, which looks at movement and speed and pushing yourself beyond normal limits, and then Social Actions, whether you are just getting along or trying to manipulate the situation to your own ends, and thence on to Fighting. Combat involves a roll of your Attack against your target's Defence, each with a collection of bonuses based on Role and level and other factors. But you always miss on a 1 and hit on a natural 20, irrespective of bonuses or what the other fellow's Defence happens to be. Fairly normal so far... until an attack connects. Rather than the attacker rolling damage, the target rolls against his Toughness, with the Difficulty including the weapon's damage bonus... success means no damage is taken, but if the roll is less than the Difficulty damage is taken depending on how far below it was. Rather than deducting 'hit points' though, the target becomes bruised or disabled or some other descriptor based on how badly the roll was missed and whether the potential damage was lethal or subdual. It sounds more complex than it is once you start brawling. Naturally, the next part of the chapter looks at recovery and healing, before rounding out with a discussion of environmental hazards and their effects.

Chapter 7: Narrating the Game looks at the role of the Narrator (Game Master). This starts off with the crux of the matter, if you have grasped the core mechanic of D20 roll + appropriate modifiers against a Difficulty, then it does not matter what characters are trying to do, you can make it happen (or not). It's fine if you want to go into extra detail and use more complex rules, but there is no need to do so. It is good to see this stated openly, although I am sure that I am not the only GM who has been doing similar 'rules-light' abstractions for years!

A few times, mention has been made about characters gaining 'levels' and now it is revealed how - it's when the Narrator decides. No calculating XP totals and keeping track of them... it is up to the Narrator to decide when a character (or even the whole group) have done enough to level up. The rest of the Narrator chapter looks at some of the ways you can use the rules mechanics to make the game enjoyable, fast and fun... and it's probably something all Game Masters need to read even if this is not their chosen system. Get to the core of your chosen mechanic, and be ready to abstract as and when necessary so that the flow of the game is not impeded... of course, this system is designed with this aim in mind, but many of the concepts are transferrable to other rulesets if that's the sort of game you want.

Chapter 8: Adversaries provides some sample opponents for your characters. It begins by considering Narrator characters from the main villain to minions and ordinary bystanders, before going on to look at the more conventional 'monster' concept. They are all presented in fairly broad template form, but there are so many monster books out there that finding some good ones is a trivial task, just pare down the statistics to suit this ruleset. The chapter ends with a bestiary, some are common creatures which might turn up in any setting, fantasy or otherwise; while others are genuine monsters.

Just over half-way through the book, and that's the ruleset done and dusted. The rest is 'Worlds of Adventure' - four settings specifically designed (as the result of a competition) to be used with the True20 system. What is of interest is that each customises the ruleset to some level, adding and modifying as necessary to create the right alternate reality while retaining the core mechanics. The four settings - each from a different publisher - are Caliphate Nights (Paradigm Concepts), Lux Aeternum (BlackWyrm Games), Mecha vs. Kaiju (Big Finger Games) and Borrowed Time (Electric Mulch); and there is also mention of the Blue Rose RPG, Damnation Decade and True20 Worlds of Adventure, all published by Green Ronin.

Caliphate Nights is classic fantasy adventuring in the kind of world portrayed in One Thousand Nights and a Night, the mythical Arabia full of djinn and high adventure. After explaining the roots of the setting in traditional Arabic and Indian literature, rather than Hollywood movies, this section goes on to present the background of the setting: its history, society, religion, culture and geography. It's refreshing to read a piece on Arabia written by someone who understands something of Islam - for understanding the development of Islam is core to getting into this alternate reality of a fantastic Arabia. However, this moves seamlessly into the imagined history of the rise of a mad Caliph that forms the contemporary background of the setting.

Background explained, we move on to how characters will work within this setting. Based on the core Roles, several Archetypes are available for you to choose from - so Adepts may be astrologers, or elementalists or sha'ir (djinn-summoners0 and the like; and the same for the other Roles. For each, appropriate Feats and Skills are suggested and there is a wide selection of new Feats - how about Grooming, which confers the ability to make others look their best? Essential if you are a Barber... New Powers are also provided for Adepts to master. There are also some interesting ways of using Conviction to enhance the storytelling aspects of the game, for example you can tell a story within the overall game to explore a particular point, with the player who came up with the idea taking over as Narrator for a brief while and everyone else taking roles in this tale. Strange, but somehow fitting within this alternate reality.

Next are some notes for the Narrator. Notes on pace and setting the scene, ideas for some areas in which conflict and adventure can be found - and a list of 20 adventure ideas to start you off. Suitable monsters, and notes and game mechanics for the making and granting of wishes round this off. A good working familiarity with Arabian - and perhaps Indian or even Chinese - folklore and legend will be an advantage if you want to run this setting, you should at the very least read One Thousand Nights and A Night.

Lux Aeturnum is a swashbuckling spacefaring alternate reality. Take 17th century piratical attitudes and mix in some spaceships and sorcery and get cinematic. There's a lot going on, of course, but no deep background is required. A handful of different races have congregated in a small cluster of star systems, brought there by a strangely benevolent elder race who have banned weapons of mass destruction or even ones which kill indiscriminately - hence swords have become popular again. Of course, there is a lot going on, a swirling melee of intrigue and opportunism for characters to get involved with. Rule mechanics are quite light, as befits the cinematic feel, with a note that those looking to run combat between starships will do best to stick to abstraction and narrative, if they want more detail the best route will be to adapt another game's starship combat rules. Naturally, you do find out how to create characters from the various species around, but that's about it.

Next comes Mecha vs. Kaiju. This setting is Japanese pop culture, humans piloting giant war machines (mecha) in combat against horribly-mutated radioactive monsters (kaiju). Think of the TV series Power Rangers, Godzilla movies and anime. Oh, and if you get bored thumping monsters, there's a massive conspiracy against civilisation as you know it to combat during down-time from piloting your mecha. The whole setting can be summed up in one page, then on to character creation. Mecha pilots are the best of the best, so you get 10 points rather than the core rules 6 to enhance your abilities. While Roles stay as the core Adept, Expert and Warrior; you then choose an Archetype which brings a virtue, a vice and a whole way of looking at things to define your character. Then there's a whole bunch of Feats - a lot, of course, devoted to mecha piloting, but there's plenty more besides. Next come the mecha themselves and their weapon and other systems; and rule mechanics for mecha movement and combat. Next the opposition, all you need to run effective kaiju monsters. The section ends with adventure ideas and plot hooks to get you going.

Finally, we have Borrowed Time. It's more a concept than a setting - the idea that while time normally flows past to future one second at a time, certain individuals collect 'pockets' of spare time and use them to influence events. You can make this the core of your adventures, or use these concepts to link several diverse settings which your characters can transfer between... endless possibilities here.

Game mechanics follow: time manipulation Feats, of course, and the mechanics for speeding or slowing time - thus enabling you to do something you would not otherwise be able to do. Next come a collection of 'Factions' - groups and individuals involved in this fiddling with time, who may be allies or enemies - or competitors. One might even be the group to which the characters belong. Then there's advice on actually playing this game, which is intended for a high action style. It's excellent advice and worth reading even if you don't want to use this setting or even use a full-blown high action style... although the final bit on 'being stylish' seems to equate style with popular fashion - one quick look around my students demonstrates that dressing in the height of fashion often completely lacks style!

The book rounds out with notes on converting 'standard' D20 materials for use with the True20 game mechanic. Very useful if you desire the flexibility of this system but want to use background from other games.

Overall, this is a splendid set of game mechanics. For me, its main advantage is the free-flowing approach to rules, ensuring that they do not intrude on the actual role-playing. A second major advantage is the versitility - by making the core rules particularly for character creation extremely broad and inclusive, it is easy to refine them to suit a particular alternate reality of your choice - especially if you like to draw on your favourite fantasy novels... you can create characters that fit precisely rather than try to shoehorn standard D20 classes into the setting, as you are given the tools to write roles according to your needs.